The comparative effectiveness and safety of three activated irrigation techniques in the isthmus area using a transparent tooth model.

AIM: To compare the effectiveness and safety of three activated irrigation techniques when removing pulp tissue from the isthmus of a transparent tooth model. The three techniques assessed were: the EndoVac (EV), passive ultrasonic irrigation (PUI) and ultrasonic wave aspiration (TUWA). Conventional syringe irrigation (CSI) was used as a control. METHODOLOGY: A transparent tooth model was created using the mesial root of an extracted mandibular first molar that had an isthmus and two independent mesial canals. An artificial 0.3-mL cylindrical chamber was created below the apical foramen. The tooth was then cleared. After preparation, the root canals were filled with fuchsine-stained bovine pulp tissue. The irrigation protocols were compared in respect of their effectiveness at removing pulp tissue from the isthmus and their safety with regard to irrigant extrusion. For all four groups, 5.25% sodium hypochlorite solution was used as the irrigant. Photographs were taken and analysed using an imaging software. A Kruskal-Wallis test was used to detect the differences between groups (statistical significance was set at P < 0.05). RESULTS: No group was associated with extrusion of irrigant beyond the apex. Significant differences were observed between the groups: TUWA was the most effective technique at removing pulp tissue from the isthmus (3.39 mm2 ; standard deviation (SD) = 0.67; range = 1.25-3.69), followed by PUI (2.16 mm2; SD = 0.38; range = 1.37-2.96), EV (0.73 mm2 ; SD = 0.14; range = 0.49-0.98) and CSI (0.27 mm2 ; SD = 0.01; range = 0.26-0.28). CONCLUSION: Ultrasonic wave aspiration was the most effective technique at removing artificial pulp tissue from the isthmus of a transparent tooth model. None of the techniques extruded irrigant.

A technique for placement of apical MTA plugs using modified Thermafil carriers for the filling of canals with wide apices.

AIM: To describe a technique for the placement of apical Mineral trioxide aggregate (MTA) plugs in canals with wide apices. SUMMARY: A novel technique to fill root canals with an apical diameter larger than 0.4 mm is presented. The technique includes three main stages; three Thermafil carriers of increasing size, previously de-sheathed by removing the Gutta-percha coating, are selected to engage 1, 2 and 3 mm short of the apex. Their use allows the negotiation of acute curvatures and ledged canals. Subsequently, an MTA plug matching the apical gauge is pre-formed with a pellet block, placed and condensed using the modified carriers in sequence. The presented protocol for the management of teeth with apices of a diameter greater than 0.4 mm allows a favourable apical control of the MTA. Clinical cases completed using this methodology are presented. KEY LEARNING POINTS: MTA placement in teeth with wide apices was facilitated by using de-sheathed Thermafil carriers, to create an appropriate seal and stable platform for Gutta-percha backfilling or subsequent fibre post placement. The use of de-sheathed Thermafil carriers of different sizes allows predictable placement of pre-formed MTA plugs. Gauging of Thermafil carriers enhances control of the condensation phase to limit the extrusion of MTA.

[Root resorption. 1. Etiopathogenesis, diagnosis and clinical manifestations]. / I riassorbimenti radicolari. Parte I. Eziopatogenesi, diagnosi e manifestazioni cliniche.

The authors, after having thoroughly reviewed the literature regarding all types of root resorption, specifically investigated those of clear endodontic pertinence, and evaluated the etiopathogenesis, the possibility of diagnosis, and the clinical incidence.

Abnormalities of short-latency somatosensory evoked potentials in parkinsonian patients.

Twenty-two patients (16 affected by parkinsonian syndromes, 6 by other neurological diseases) and 12 age-matched controls were examined. Short-latency somatosensory evoked potentials were recorded from 30 scalp electrodes in the 45-52 msec following separate left and right median nerve stimulation at the wrist. Bit-colour maps were generated on a 4096 pixel matrix via quadratic interpolation. Peak latencies and amplitudes of the parietal, central and frontal components were evaluated. Moreover, the amplitude ratios between parietal and frontal components on the same hemiscalp and between peaks on homologous right and left scalp districts were taken into account. The unique significant difference between parkinsonians and controls was represented by a depressed frontal N30 wave. This peak was absent in 3 and reduced in 7 out of 16 parkinsonians, with an overall abnormality rate of 47% of the examined arms. Average maps pooling data of parkinsonians and controls confirmed the presence of reduced evoked activity for the whole duration of wave N30 on those mid- and parasagittal frontal districts where this peak is maximally represented in normals. A similar abnormality was found in 1 of the 6 non-parkinsonian neurological patients suffering from a meningioma of the falx compressing the left supplementary motor area. Possible pathophysiology of such wave N30 abnormalities in parkinsonians is discussed.